1. Field of the Invention
The invention relates to resin or other film-forming agent based biological dressings that adhere to the skin and contain one or more pharmacologically active agents for the treatment of symptoms relating to dermatological diseases and those affecting mucous membranes. The invention is exemplified by biological dressings comprising tincture of benzoin and clotrimazole for the treatment of athlete's foot and by biological dressings comprising mastic and ciclopirox for onychomycosis.
2. Background Information
For many forms of dermatological conditions, the powders, sprays, solutions, lotions and creams available over-the-counter lack effectiveness. The reason for this varies, from poor delivery of the medication to the source or cause of the condition, to loss of the medication through abrasion from normal activity of the patient, to absorption of medications applied to the skin by the patient's socks or clothes. For these various reasons, currently available commercial medications are prone to come off easily once applied to the affected area, and consequently much of the medication is wasted, either through over application in an attempt to anticipate the problem, or in medicine quickly being dispersed away from the site. The medications for these conditions typically require at least 2 to 4 weeks of continuous treatment, and thus often fail due to this poor delivery.
A further problem with the use of existent medications is the lack of compliance by patients. Due to the mess and difficulty of use, patients will often use these over the counter medications only until their symptoms abate and then they will stop the medication, before the recommended course of treatment is completed, and hence often before the infection has truly cleared. Though momentarily abated, the infection then begins to take hold again, and in a matter of days or weeks a full blown infection occurs again. In many cases the patient will repeat using the over the counter medication until the symptoms clear, and again stop the medication with the first sign of abatement, with the whole cycle repeating.
Hence, there is a need for a clean and inexpensive vehicle/carrier of topically applied medications that increases the convenience and effectiveness of the treatment and decreases the necessary time for the treatment. It is preferably associated with less waste and lower cost, and ultimately leads to improved treatment of patient symptoms and increased patient satisfaction.
In medicine, tincture of benzoin and mastic gum (Mastisol) have been employed to form a sticky coating on skin prior to the placement of adhesive preparations. Tincture of benzoin has also been used to form a biologic dressing over superficial cutaneous wounds as well as aphthous ulcers (canker sores). However, the general use of resins, such as mastic and benzoin gum, as semi-permanently applied carriers for increasing the efficacy and usefulness of topological of pharmacological agents has not been disclosed.
A tincture of benzoin has been used with podophyllin resin (10-25%) in the treatment of genital warts. It is considered by many to be cumbersome and inconvenient (see U.S. Pat. Nos. 5,063,065 and 5,167,649). Unfortunately, podophyllin resin is toxic, and even when applied in a tincture of benzoin, this agent must be removed by rigorous washing 1 to 6 hours post-application. Due to the problems associated with using podophyllin resin in tincture of benzoin, other carriers have been sought. As an example, in the treatment of genital warts, Goh, et al. (Singapore Med J (1998) 39:17-19) reports that podophyllin prepared in 0.25% ethanol can be self-applied and is as efficacious as podophyllin prepared in tincture of benzoin and applied in the clinic. Use of tincture of benzoin as a biological bandage with compounds that it is desirable to have in long contact with the skin has not been reported.